Reproduction apparatus and method

ABSTRACT

To be capable of obtaining diffuse light with a sufficient amount of light, which is not susceptible to the influence of scratches of a film along the length direction, and to be capable of constructing the apparatus in a small size and at a low cost, a digital audio signal S track or P track is formed on the side of the film furtherest to the left of the left perforations or to the right of right perforations of a movie film, respectively. Light from an LED 51 is diffused by an elliptical diffuser 52, the diffusion angle of which is greater along the width direction of the film than along the length direction thereof, and is radiated onto the P track (or the S track). Then, the transmitted light which has passed through the P track (or the S track) is converged onto a line sensor 43A as a result of passing through a lens 42A, and the light is photoelectrically converted by the line sensor 43A, thereby reproducing digital sound.

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention relates to a reproduction apparatus and methodand, more particularly, to a reproduction apparatus and method suitablefor use in a case in which, for example, digital sound data and the likerecorded on a movie film is reproduced.

2. Description of Related Art

FIG. 8 shows the construction of an example of a conventional moviefilm. A movie film 1 is, for example, a 35 mm movie film used in movietheaters, with perforations, serving as feed holes used to obtainfeeding synchronization, being formed at predetermined intervals on bothend portions of the movie film along the width direction. Further,picture frames (commonly called frames) in which an image is opticallyrecorded are formed in the central portion thereof along the widthdirection. Here, the length of the picture frame along the lengthdirection is, for example, 19.05 mm, and for one picture frame, forexample, four perforations are formed on both the right and the left.

Between the picture frames and perforations on the right (rightperforations in FIG. 8), analog tracks are provided, an analog soundsignal being formed optically therein.

Meanwhile, as CD (Compact Disc) players and other digital audioequipment have become widespread into ordinary households in recentyears, there has been an increased demand for digitization of moviesound. Accordingly, recently a technique is becoming popular in whichdigital sound, in addition to analog sound, is recorded on a movie film,and digital sound is normally used and analog sound is used as aback-up.

Various methods of recording digital sound on a movie film have beenproposed. As one of them, there is a SDDS (Sony Dynamic Digital Sound)(trademark) method in which, as shown in FIG. 8, a P track or a S trackis provided on the side further to the left of the left perforations oron the side further to the right of the right perforations, and pits inthe form of dots are formed therein, thus recording digital sound. Inthe SDDS method, for example, as shown in FIG. 9, rectangular pits(dots), which are 24 microns along the width direction and 22.5 micronsalong the length direction, are recorded optically in a mannercorresponding to digital sound. The pitch along the length direction is,for example, 26.5 microns.

Reproduction of the P tracks and the S tracks in which digital sound isrecorded is performed, for example, along the length direction with apit sequence formed along the width direction being one unit.

FIG. 10 shows the principle of the reproduction method for reproducingdigital sound. For example, light emitted from a light source, forexample, an LED (light-emitting diode) 101 or a halogen lamp, isradiated on the P tracks and the S tracks of the movie film 1 via anoptical fiber 102. The light radiated onto the P tracks and the S trackspasses therethrough in a manner corresponding to the pits formedtherein, and the transmitted light enters a lens 103. The transmittedlight from the movie film 1 is converged by the lens 103 onto linesensors 104, such as a line CCD (charge coupled device). In the linesensors 104, the light is photoelectrically converted into an electricalsignal corresponding to dots for one line along the width direction.This electrical signal is provided to a decoder 105 whereby it isdecoded into digital sound, and is output from a speaker 107 via anamplifier 106.

In the SDDS method, for example, eight-channel sound output is madepossible: the screen center (center) in which an image is projected, theright and left thereof (left and right), between the center and the left(left center), between the center and the right (right center),subwoofer, left surround, and right surround.

Further, in the SDDS method, digital sound is coded by a coding methodcalled ATRAC (Adaptive TRansform Acoustic Coding) adopted in mini-discs(trademark), achieving a data compression rate of about 1/5. In thedecoder 105, decoding of data which is coded by this ATRAC method, andothers is performed.

In the case where the reproduction of the P tracks and the S tracks suchas that described above is performed, in order that the readingcharacteristics are maintained to some degree, it is required that thelight-amount distribution in the line sensors 104 be uniformly formed.Here, the formation of a uniform light-amount distribution refers to theoutput of the line sensors 104 becoming almost uniform as shown in FIG.11 when it is assumed that the entire movie film 1 is uniformlytransparent. Specifically, it means that the ratio of the minimum outputto the maximum output (minimum output/maximum output) in a particularline of the line sensors 104 becomes a predetermined standard value ormore.

In order to cause the S/N (Signal/Noise) ratio of the line sensors 104to be a predetermined value or more, the amount of light which reacheseach pixel of the line sensors 104 must be nearly constant regardless ofthe pixel position of the line sensors 104.

Also, the movie film 1 is constructed in such a way that a layer ofemulsion is formed on a base, as shown in FIG. 12A, and pits as digitalsound are formed by optically discoloring the emulsion. Since theprojection thereof is performed by causing the movie film 1 to be fedalong the length direction, as shown in FIG. 12B, a number of finescratches which are extended along the length direction are ordinarilyformed on the base. In order to prevent (reduce) an occurrence of pitreading errors due to these scratches, it is required that the light tobe radiated onto the movie film 1 be diffuse light.

Conventionally, because of the above, an illumination optical system ofa reproduction apparatus which reproduces digital sound is constructedas shown, for example, in the perspective view of FIG. 13.

That is, in order that the amount of light which passes through the film1, the lens 103, and reaches each pixel regardless of the pixel positionin the line sensor 104 is constant, the optical fiber 102 is constructedby using about 10,000 very small fibers having, for example, a diameterof approximately 50 mm, and these are made to branch into bundles ofabout 2,500 each as very small fibers 102₁, 102₂, 102₃, and 102₄.Further, the very small fibers 102₁ to 102₄ are arrayed, for example, insuch a manner as to be twisted so that the positional relationship ofboth the end surfaces becomes random, thereby causing the light whichexits from the optical fiber 102 to be constant.

Further, to make the light to be radiated onto the movie film 1 diffuselight, in addition to an LED 101₁ which emits light which is parallel tothe optical axis of the optical fiber 102, LEDs 101₂ and 101₃ which emitlight which forms a predetermined angle, other than 0 degrees, withrespect to the optical axis of the optical fiber 102 are provided so asto form light (diffuse light) having a high degree of diffusion. In thiscase, when light is diffused in this manner, as shown in FIGS. 14A and14B, diffuse light having the same diffusion angle (40 degrees in FIGS.14A and 14B) is emitted from the optical fiber 102 in both the widthdirection (XIVA--XIVA direction) and the length direction (XIVB--XIVBdirection).

Further, it is difficult for one set of LEDs 101₁ to 101₃ to obtain asufficient amount of light, and loss in the amount of light is largeduring input and output of light to and from the optical fibers 4.Therefore, conventionally, for example, an additional three sets of LEDssimilar to LEDs 101₁ to 101₃ are prepared, and a total of 12 LEDs (=3×4sets) are used to maintain the intensity of light.

In order to maintain the intensity of light, there is a method using,instead of an LED, for example, a halogen lamp having an intensityhigher than that of an LED. However, halogen lamps generally have adrawback that their service life is shorter than that of an LED.

Therefore, conventionally, as an illumination optical system forreproducing two tracks of an S track and a P track in which digitalsound is recorded, two sets of optical fibers formed of 12 LEDs and fourvery small fibers are required, presenting the problem that theapparatus has a higher cost and becomes enlarged.

SUMMARY OF INVENTION

The present invention has been achieved in view of such circumstancesand makes it possible to construct the apparatus in a small size and ata low cost. The reproduction apparatus method according to the inventiondiffuses light from a source into diffuse light, which light is radiatedonto a film on which data is recorded in the form of dots. The diffusionangle of the diffuse light is greater along the width direction of thefilm than along the length direction thereof Therefore, it is possibleto obtain diffuse light with a sufficient amount of light, which is notsusceptible to the influence of scratches of a film along the lengthdirection.

The foregoing and other objectives, features and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of certain preferred embodiments of theinvention, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing an example of the construction of anembodiment of a projection system of the present invention.

FIG. 2 is a plan view showing an example of the construction of a reader3 of FIG. 1.

FIG. 3 is a sectional view when the reader 3 of FIG. 2 is viewed fromthe III--III direction.

FIG. 4 is a perspective view showing an example of the construction of alight-source section 41A of FIG. 2.

FIG. 5 is a view showing the characteristics of a diffuser 52 of FIG. 4.

FIGS. 6A and 6B are views showing the characteristics of variousdiffusers.

FIGS. 7A, 7B, and 7C are views illustrating diffuse light formed by thediffuser 52.

FIG. 8 is a plan view showing an example of the construction of a moviefilm 1.

FIG. 9 shows pits formed on the P and S tracks of FIG. 8.

FIG. 10 is a view illustrating the principle for reproducing a moviefilm of FIG. 8.

FIG. 11 is a view illustrating the formation of a uniform light-amountdistribution.

FIGS. 12A and 12B are sectional views showing an example of theconstruction of the movie film 1.

FIG. 13 is a perspective view showing an example of the construction ofa conventional illumination optical system of a reproduction apparatuswhich reproduces digital sound recorded on the movie film 1.

FIGS. 14A and 14B are views illustrating diffuse light emitted from anoptical fiber 102 of FIG. 13.

DESCRIPTION OF PREFERRED EMBODIMENTS

Before the embodiment of the present invention is described below, inorder to clarify the corresponding relationship between each means ofthe invention described in the claims and the following embodiment, oneexample of the corresponding embodiment is added to the parenthesesafter each means, and the features of the present invention will now bedescribed.

The reproduction apparatus according to one embodiment of the inventionreproduces data recorded in the form of dots on a film, and comprises alight source (for example, an LED 51 shown in FIG. 4) for emitting lightto be radiated onto the film; a diffuser (for example, an ellipticaldiffuser 52 shown in FIG. 4) for diffusing light from the light sourceinto diffuse light; and photoelectric-conversion means (for example, aline sensor 43A shown in FIG. 4) which photoelectrically convertstransmitted light or reflected light obtained by radiating the diffuselight onto the film. The diffusion angle of the elliptical diffuser 52is greater along the width direction of the film than along the lengthdirection thereof. It is a matter of course that this description doesnot mean that each means is limited to those described above.

FIG. 1 shows the construction of an embodiment of a projection system(system refers to a logical assembly of a plurality of apparatuses, andit does not matter whether the apparatus of each construction is withinthe same housing) of the present invention.

For example, a movie film 1 in which digital sound is recorded by anSDDS method as shown in FIG. 8 is wound around a supply reel 2. Themovie film 1 is taken out from the supply reel 2 and inserted into areader 3. The reader 3 reads pits as digital sound recorded on the moviefilm 1 and supplies an electrical signal as the result of the reading toa decoder 4. The decoder 4, an amplifier 5, and a speaker 6 correspondto the decoder 105, the amplifier 106, and the speaker 107,respectively, shown in FIG. 10. In the decoder 4, a signal from thereader 3 is decoded into digital sound and output from the speaker 6 viathe amplifier 5.

The movie film 1, whose pits are read by the reader 3, is fed to aprojector 7, whereby an image recorded on the movie film 1 is projectedon a screen (not shown) by light from a light-source section 8. Further,in the projector 7, sound (analog sound) of analog tracks recorded onthe movie film 1 is reproduced by light from the light-source section 8and supplied to the decoder 4. When, for example, an error occurs indigital sound, the decoder 4 causes analog sound as a back-up, insteadof the digital sound, to be output from the speaker 6.

The movie film 1, such that the image and analog sound are reproduced,is fed from the projector 7 and supplied to a take-up reel 10. In thetake-up reel 10, the movie film 1 from the projector 7 is taken up.

Next, FIGS. 2 and 3 show an example of the mechanical construction ofthe reader 3 of FIG. 1. FIG. 3 is a sectional view of FIG. 2 viewedalong the III--III direction. In FIG. 3, an illustration of points otherthan the movie film 1, a drum 28, light-source sections 41A and 41B,lenses 42A and 42B, and line sensors 43A and 43B is omitted to avoid acomplex figure.

The movie film 1 is hooked to a guide roller 21 and guided to a guideroller 23 around a guide roller 22. The guide roller 23 is urged by aspring (not shown) and functions as a stabilizer so as to impart anappropriate tension to the movie film 1. The movie film 1 is folded byabout 90 degrees at the guide roller 23 and guided to a sprocket 25 by aguide roller 24.

The perforations of the movie film 1 are hooked to the teeth formed onthe periphery (outside surface) of the sprocket 25 and fed thereby.Press rollers 26 and 30 are urged in the direction of the sprocket 25by, for example, a spring, and press the central portion (the centralportion along the width direction) of the movie film 1 to the sprocket25, causing the movie film 1 to be in close contact with the sprocket25.

The movie film 1 fed from the sprocket 25 is given an appropriatetension via a guide roller 27 urged by, for example, a spring and isguided to the drum 28. The movie film 1 is folded back by about 180degrees around the drum 28 and fed to the sprocket 25 via a guide roller29. Here, the guide roller 29 is urged by, for example, a spring andgives an appropriate tension to the movie film 1.

The movie film 1 fed from the guide roller 29 is engaged with thesprocket 25, is folded back by about 180 degrees around the guiderollers 31 and 32, and fed to the projector 7 via a guide roller 33.

The movie film 1 is caught between the guide rollers 24 and 31 andbetween the guide rollers 27 and 29, thereby more perforations of themovie film 1 are hooked to more teeth of the sprocket 25. Further, bygiving tension to the movie film 1, the movie film 1 is brought intoclose contact with the drum 28 without slack.

In this embodiment, the feeding of the movie film 1 is performed by theprojector 7. Therefore, the reader 3 does not have motive power forfeeding the movie film 1. Further, in order to prevent the movie film 1from being slackened within the reader 3 as a result of being pulled bythe projector 7, the sprocket 25 is provided with a brake. That is, byapplying to the sprocket 25 a force in a direction opposite to thetension force of the projector 7, the movie film 1 maintains anappropriate tension and does not slacken within the reader 3.

The drum 28 has a cylindrical shape, the central portion of the twobottoms thereof is recessed from the side surface (the periphery of thedrum 28), as shown in FIG. 3, with the light-source sections 41A and 41Bfor reproducing digital sound recorded in the P track or the S trackbeing disposed in the recessed portion. For correct viewing, FIG. 3should be turned 90° clockwise. The reason why the central portion ofthe bottom of the drum 28 is recessed is for the purpose of disposingthe light-source sections 41A and 41B. In contrast, the reason why theside surface is projected more than the central portion is for thepurpose of preventing the end portions along the width direction of themovie film 1 wound around the drum 28 from being slackened in thedirection of the rotational axis of the drum 28. The width (the heightof the side surface) of the periphery of the movie film 1 is, at most,of a length such that the P and S tracks of the movie film 1 stick outfrom the drum 28.

The light-source sections 41A and 41B radiate light onto the P track andthe S track, respectively, which stick out from the drum 28. This lightpasses through the P track and the S track and is converged onto theline sensors 43A and 43B, such as a line CCD, through the lens 42A and42B, respectively. In the line sensors 43A and 43B, the transmittedlight from the P track and the S track, respectively, isphotoelectrically converted, and the resulting electrical signals aresupplied to the decoder 4.

The perspective view of FIG. 4 shows an example of the construction ofthe light-source section 41A of FIG. 3. Since the light-source section41B is constructed the same as the light-source section 41A, adescription thereof has been omitted (an illustration thereof has alsobeen omitted).

The light-source section 41A comprises a light source, for example, theLED 51, which emits light to be radiated onto a pit sequence (pitsequence along the width direction) as digital sound formed on the Ptrack, and a diffuser 52 for diffusing the light into diffuse light andradiating it onto the P track.

The diffuser 52 is, for example, an elliptical diffuser for forming thelight from the LED 51 into diffuse light, the diffusion angle of whichis greater along the width direction of the movie film 1 than along thelength direction thereof. Thus, the light to be radiated onto the Ptrack is formed into diffuse light so that a reading error of pits,caused by scratches formed along the length direction on the movie film1, can be prevented (reduced) and such that the amount of light issufficient and uniform (the minimum output/maximum output of the linesensor 43A is made to exceed a predetermined standard value).

FIG. 6A shows the results of the investigation of the diffusion angle ofvarious diffusers and the amount of light, conducted by the inventors ofthe present invention. FIG. 6A shows the relationship between thediffusion angle, and the light-amount loss in the direction of thediffusion angle with respect to the light in the direction of 0 degree(in the direction of the optical axis). Further, in FIG. 6B, thenumerals represented in percent within the parentheses () show theamount of the diffuse light obtained by each diffuser with, for example,the amount of light used in a reader (model No: DFP-R2000) manufacturedby Sony Corporation as a reference (100%).

Here, in the reader DFP-R2000 manufactured by Sony Corporation, asdescribed in FIG. 13, to read one track (S track or P track), an opticalfiber formed of four very small fibers and 12 LEDs is used.

When the degree of diffusion (diffusion angle) is taken note of, it canbe seen from FIG. 6A that a holographic diffuser 40 has characteristicswhich most resemble those of the light adopted in the reader DFP-R2000.In this case, however, as shown in FIG. 6B, the amount of light is 53%,and it is difficult to obtain a sufficient amount of light. On the otherhand, when the amount of light is taken note of, it can be seen fromFIG. 6B that the use of a holographic diffuser 20 makes it possible toobtain an amount of light equal to the light adopted in the readerDFP-R2000. In this case, however, as shown in FIG. 6A, the diffusionangle is decreased (becomes almost half of that in the case of thereader DFP-R2000).

As described above, in each of the diffusers shown in FIG. 6B, one ofthe degree of diffusion and the amount of light (the amount of light inthe case of direct illumination by a single LED) is not sufficient.

Accordingly, as the diffuser 52, here, an elliptical diffuser is adoptedwhich has a sufficient degree of diffusion, for example, characteristicscomparable to those of a holographic diffuser 60, along the widthdirection of the movie film 1, though the amount of light isinsufficient, and which has a sufficient amount of light, for example,characteristics comparable to those of a holographic diffuser 10, alongthe length direction, though the degree of diffusion is insufficient.

As a result, in the diffuser 52, for example, as shown in FIGS. 7A and7B, diffuse light having a diffusion angle up to about 60 degrees isemitted along the width direction (the VIIA--VIIA direction in FIG. 4),and diffuse light having a diffusion angle up to about 10 degrees isemitted along the length direction (the VIIB--VIIB direction in FIG. 4).As a result, an elliptical light spot extended along the widthdirection, such as that shown in FIG. 7C, is formed in the P track.

In this case, the degree of diffusion along the length direction issmaller than that of the conventional case (for example, light adoptedin the reader DFP-R2000). However, since most of scratches formed in themovie film 1 are along the length direction, the small degree ofdiffusion along the length direction hardly exerts an influence upon thereading error of pits resulting from such scratches. That is, by causingthe degree of diffusion along the width direction to be greater than orequal to that of the conventional case, the reading error of pitsresulting from scratches along the length direction can be prevented(reduced).

On the other hand, a decrease in the amount of light caused by causingthe degree of diffusion along the width direction to be greater than orequal to that of the conventional case can be compensated for bydecreasing the degree of diffusion along the length direction.

The amount of light is made uniform by causing the variation in theamount of light from the LED 51 to be uniform by the diffuser 52.

From the above, it is possible to obtain diffuse light, whose amount oflight is sufficient and which is made uniform and has a sufficientdegree of diffusion by one LED 51.

Therefore, since the light-source section 41A as an illumination opticalsystem may be formed of one LED 51 and one diffuser 52, the apparatuscan be constructed in a small size and at a low cost. Specifically, thenumber of required LEDs can be one twelfth the case in FIG. 13. Also, inFIG. 13, the volume of the portion occupied by twelve LEDs 101 and theoptical fiber 102 can be about one tenth by forming the portion of theLED 51 and the diffuser 52.

Further, since the degree of diffusion along the width direction can bemade greater than or equal to that of the conventional case in a rangein which a decrease in the amount of light can be compensated for bydecreasing the degree of diffusion along the length direction, itbecomes possible to further improve the tolerance to scratches along thelength direction. As a result, it becomes possible to increase the limitof the number of times the movie film can be used.

Although in this embodiment an elliptical diffuser is used to diffuselight more strongly along the width direction of the movie film thanalong the length direction, other means may be used to achieve the sameeffect.

Although in this embodiment data in the form of dots as digital soundrecorded on a movie film is reproduced by light diffused by theelliptical diffuser, in addition to this case, it is also possible toreproduce an image and analog sound recorded on the movie film.

Although in this embodiment a movie film on which digital sound isrecorded by an SDDS method is targeted, the present invention may beapplied to a case in which digital sound recorded by other methods isreproduced. That is, as a technique for recording digital sound on amovie film, for example, there is an SR-D method of the Dolby Co., Ltd.for recording digital sound between perforations, and the presentinvention may be applied to such a method.

Although in this embodiment data in the form of dots as digital sound isreproduced, the present invention may be applied to a case in which, forexample, subtitles and other information other than digital sound arerecorded as data in the form of dots.

There is a case in which, for example, digital sound is recorded on a CDand a time code for obtaining synchronization with the digital sound isrecorded on a movie film (a digital film sound system of the DTS Co.,Ltd.). The present invention may be applied to a case in which such atime code recorded on a movie film is reproduced.

Although in this embodiment a movie film is targeted, the presentinvention may be applied to any apparatus which reproduces informationfrom a film on which information is recorded, other than a movie film.

Although in this embodiment transmitted light which passes through amovie film is photoelectrically converted, in addition, the presentinvention may also be applied to a case in which light reflected by amovie film is photoelectrically converted.

Although in this embodiment an LED is used as a light source forradiating light onto a movie film, the light source is not limited to anLED.

According to the reproduction apparatus and method of the invention,light to be radiated onto a film on which data is recorded in the formof dots is diffused by a diffuser into diffuse light, the diffusionangle of which is greater along the width direction of the film thanalong the length direction thereof. Therefore, it is possible to achievea small size and a low cost of the apparatus. It is also possible toobtain diffuse light with a sufficient amount of light, which is notsusceptible to the influence of scratches of a film along the lengthdirection.

Although the present invention has been shown and described with respectto preferred embodiments, various changes and modifications are deemedto lie within the spirit and scope of the invention as claimed. Thecorresponding structures, materials, acts, and equivalents of all meansor step plus function elements in the claims which follow are intendedto include any structure, material, or acts for performing the functionsin combination with other claimed elements as specifically claimed.

What is claimed is:
 1. A reproduction apparatus for reproducing datarecorded in the form of dots on a film, the reproduction apparatuscomprising:a light source for emitting light; a diffuser interposedbetween the light source and the film for diffusing light from the lightsource into diffuse light which is radiated onto the dots on the filmwith the diffusion angle of the diffuse light being greater along thewidth direction of the film than along the length direction thereof; andphotoelectric detector which photoelectrically converts the diffuselight which is modulated by the dots on the film into an electricalsignal.
 2. A reproduction apparatus according to claim 1, wherein thediffuser is an elliptical diffuser.
 3. A reproduction apparatusaccording to claim 1, wherein the diffuser has a diffusion angle ofabout 60° along the width direction of the film and about 10° along thelength direction thereof.
 4. A reproduction apparatus according to claim1, wherein the photoelectric detector detects modulated diffuse lightpassing through the film.
 5. A reproduction apparatus according to claim1, wherein the photoelectric detector detects modulated diffuse lightreflected by the film.
 6. A reproduction apparatus according to claim 1,wherein the dots represent one or more digital sound tracks on the filmand the electrical signal is representative of one or more soundsignals.
 7. A reproduction apparatus according to claim 1, wherein thedots are arranged in sequences of lines along the width direction of thefilm.
 8. A reproduction apparatus according to claim 1, wherein the dotsare arranged on the film between a line of sprocket holes extendingalong the length of the film and an edge of the film which is closest tothe line of sprocket holes.
 9. A reproduction apparatus according toclaim 1, wherein the light source is at least one light emitting diode.10. A reproduction method for reproducing data recorded in the form ofdots on a film, the reproduction method comprising the steps of:emittinglight; diffusing the emitted light into diffuse light to be radiatedonto the film, wherein the diffusion angle of the diffuse light isgreater along the width direction of the film than along the lengthdirection thereof; and photoelectrically converting the diffuse lightwhich is modulated by the dots on the film into an electrical signal.11. A reproduction method according to claim 10, wherein the diffusingstep includes the step of diffusing light with an elliptical diffuser.12. A reproduction method according to claim 10, wherein the diffusingstep diffuses at an angle of about 60° along the width direction of thefilm and about 10° along the length direction thereof.
 13. Areproduction method according to claim 10, wherein the photoelectricconverting step converts modulated diffuse light passing through thefilm into an electrical signal.
 14. A reproduction method according toclaim 10, wherein the photoelectric converting step converts modulateddiffuse light reflected by the film into an electrical signal.
 15. Areproduction method according to claim 10, wherein the dots representone or more digital sound tracks on the film and the electrical signalis representative of one or more sound signals.
 16. A reproductionapparatus according to claim 10, wherein the step of emitting lightcomprises emitting light from at least one light emitting diode.